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1.
近几年,设施农业保护地栽培得到迅速发展,尤其保护地黄瓜栽培发展迅速扩大,但在发展过程中,由于受连作栽培和不合理的化肥使用与耕作方式的诸因素影响,不仅导致了土壤污染,酸化板结,理化性状变劣,化肥利用率降低,而且还造成了保护地黄瓜产量品质难以得 相似文献
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项硕 《广西农业生物科学》2000,19(4):247
应我校农学院邀请,日本岐阜大学农学部教授福井博一博士于2000年8月19日～25日来访.福井教授主要从事园艺植物的工厂化生产(保护地栽培)及工厂化育苗的研究.1992年和1993年作为原广西农业大学兰花课题的合作伙伴,曾两次来校访问.此次来访,拟就我校温室、大棚等保护地栽培及组培苗科研生产等方面进行交流座谈,并到南宁市副食品局所属的有关科研、生产基地进行现场指导与交流. 相似文献
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苎麻是一种用途大,成本低,靠得住,收入多的经济作物,在我区有悠久的栽培历史。据记载“唐建中元年(公元780年)宜春郡岁贡苎布十疋”。说明赣西锦江、袁河两岸的群众,远在1200年前就有种植苎麻的习惯和经验。目前在大力发展多种经营中,上高县也把苎麻列为重点,在进行农业气候区划中,我们对上高县苎麻生产中应注意的几个农业气象问题作了分析,并对该县苎麻生产的农业气候分区作了划分和评述,现介绍如下: 相似文献
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<正> 草莓是多年生草本植物,具有结果快、成熟早、栽培和更新周期短、繁殖容易、经济效益高的特点,采用各种形式的保护地栽培和露地栽培,可以做到10月到翌年6—7月都有鲜果成熟。果实含有丰富的维生素和矿物质,既可鲜食又可制成各种加工制品,所以在我国随着人民生活水平的提高和旅游、外贸业的发展,对草莓的需求量大增,栽培面积迅速扩大。 相似文献
6.
目前水分紧缺是制约保护地蔬菜产量的重要因素,如何在保证产量的前提下合理地提高水分利用效率成为保护地节水措施的重要评价指标。采用日光温室小区栽培试验的方法,对番茄产量、水分利用效率等指标进行比较,探讨了温室番茄栽培适宜的渗灌灌水控制上下限指标。结果表明:在相同灌水控制下限的条件下,番茄的产量随着灌水控制上限的升高有增加的趋势,灌水控制下限取土壤水吸力45kPa、上限12kPa,有利于番茄的生长发育,可以保证高产和节水省工的目标。 相似文献
7.
番茄的营养液膜栽培配套技术研究 总被引：1，自引：0，他引：1
营养液膜技术(Nutrient Film Technique)作为第三代水培新技术,在克服连作障碍、生产无公害蔬菜和提高蔬菜产量上具有明显优越性。作者以营养液膜技术,结合我国国情,在栽培设施、供液方式、育苗和定植方式、营养液更新方法、合适的营养液浓度和管理方法等方面,进行简易化栽培研究,使得番茄增产增值,成本大幅度降低,基本形成了现阶段我国保护地番茄营养液膜栽培配套技术规范。 相似文献
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近几年我市保护地栽培面积迅速扩大 ,但随着保护地栽培年限的延长 ,加上常年连作栽培和操作管理不当诸因素的影响 ,导致土壤耕作层盐渍化程度提高 ,造成蔬菜中亚硝酸盐含量超标 ,这就严重危害了人民身体健康。为此 ,莱西市土肥站自 1999～ 2 0 0 1年承担组织实施莱西市科委下达 相似文献
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兴建日光节能温室，进行蔬菜保护地栽培，是丘陵山区大力发展城郊上流域集约化经营的基本模式。通过对严村流域７１个温室调查分析可知，单个温室年均收入为１５８０．３元。蔬菜保护地栽培收入虽然占到年人均收入的２５．３７％，但有潜力可挖。只要今后加强技术培训，增加投入，引进优良品种，改进现有设施并且产供销配套，预计人均收入可增加到９０２－１２３７元。 相似文献
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随着国民经济的发展和人民生活水平的提高．人们对饮食的要求不再是简单的求得温饱．更多关注的是营养和食品安全。食用菌作为集营养与保健于一身的理想食品．日益受到人们的青睐．被联合国粮农组织誉为“21世纪的健康食品”。我国是食用菌生产大国．也是最早栽培、利用食用菌的国家之一．早在1100多年前已有人工栽培木耳的记载．800多年前在浙江西南部已开始栽培香菇．200多年前在闽粤一带开始栽培草菇。我国对药用菌的利用同样有着悠久的历史，东汉时的《神农本草经》记载药物365种，其中就有茯苓、猪苓、雷丸、木耳等10多种真菌。 相似文献
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Evidente A Andolfi A Cimmino A Vurro M Fracchiolla M Charudattan R 《Journal of agricultural and food chemistry》2006,54(5):1779-1783
Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds. 相似文献
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基于图像的作物病害状态表观三维模拟方法 总被引：4，自引：4，他引：0
为了解决病害表观信息难以获取导致的作物病害状态三维模拟困难的问题,该文提出一种基于图像的作物病害状态表观模拟方法。该方法首先利用单张图像提取病斑的形状、颜色以及位置特征,并对其变化过程进行自动推断;基于这些特征信息,对病害的病状以及病症表观进行建模。试验结果表明,该方法可以利用网络中已有的病斑图像对病害侵染导致的作物表观变化进行真实地三维模拟,一定程度上解决病害表观信息缺失的问题,为数字农业设计及农业科普培训动画的制作提供有力工具。 相似文献
13.
An analysis of the spatial distribution of the sodium adsorption ratio (SAR) values in the upper subsurface horizons of Vertisols made it possible to estimate the degree of sheet erosion on the dissected coastal plain composed of the sodium-bearing montmorillonite clay in Israel. The depth of the appearance of slickensides in the profile of the Vertisols was used as an additional criterion of the disturbance of these soils by erosion. The approximate rates of erosional dissection of the local landscapes after the deposition of montmorillonite clay are discussed. 相似文献
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[目的]揭示三峡库区弃渣场土壤侵蚀规律,为该地区弃渣场的土壤侵蚀治理提供依据。[方法]通过现场搭建径流小区并采用人工模拟降雨的方法进行研究。[结果]降雨量同侵蚀量存在极显著的线性关系;降雨强度同渣场产流时间呈极显著的幂函数关系,同径流含沙率呈极显著的指数函数关系;渣场表层较高的细砾石含量,一定程度上可以减少溅蚀与面蚀量,但在强降雨或持续降雨条件下会促进坡面沟蚀的发育;渣场侵蚀具有一定季节分布,非雨季时,渣场侵蚀以面蚀与轻微沟蚀为主,坡面主要发育为细沟与浅沟,侵蚀量较少;雨季时,渣场坡面浅沟迅速转化为切沟,泥沙流失严重。[结论]研究区渣场侵蚀具有一定的季节性,渣场施工时应根据气候特征适当调配,主动避开雨季,并在雨季前完成渣场的水土保护设置;采取相应防护措施抑制或减缓雨季沟蚀的发育是研究区渣场水土保持防护的重点。 相似文献
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Young JF Hansen-Møller J Oksbjerg N 《Journal of agricultural and food chemistry》2004,52(23):7158-7163
Effects of flavonoids on stress response of myotube cultures was studied by monitoring the release of [14C] taurine, leukotriene production, and 2',7'-dichlorodihydroflourescein (DCFH2) oxidation. Stress was induced by hypotonic shock, which was accompanied by cell swelling leading to increased leukotriene production and a concomitant increase in reactive oxygen species and osmolyte release. In this model system, addition of the flavonoids catechin and quercetin decreased leukotriene production, DCFH2 oxidation, and taurine efflux, indicating a reduction of cellular stress. High concentrations of epigallocatechin gallate (EGCG) and tea extract increased leukotriene production and initial DCFH2 oxidation, indicating an increased cellular stress (possibly toxicity). However, taurine efflux was reduced, and also longer exposure time as well as lower concentrations of EGCG and tea reduced DCFH2 oxidation. Trolox and alpha-tocopherol did not significantly affect taurine efflux or leukotriene production, and it was therefore concluded that suppression of these responses was not confined to redox activity in a myotube culture. 相似文献
16.
Dupin IV McKinnon BM Ryan C Boulay M Markides AJ Jones GP Williams PJ Waters EJ 《Journal of agricultural and food chemistry》2000,48(8):3098-3105
A fraction containing the mannoproteins released during fermentation from the winemaking strain of Saccharomyces cerevisiae, Maurivin PDM, was able to reduce the visible protein haze in white wine. This fraction of haze protective mannoprotein material (HPM) could be recovered by either ultrafiltration or ethanol precipitation. The kinetics of the release of both mannose- and glucose-containing polymers during the growth cycle of PDM were determined as a guide to the release of HPM. Active HPM was first detected in the culture supernatant when the cells were exponentially growing. HPM was also released into the medium under an environment simulating winemaking conditions by PDM cells during fermentation as well as during storage on yeast lees. Since the amounts of HPM released during fermentation are greater than those subsequently extracted from the cell wall, fermentation would be a more viable procedure than extraction from yeast cells for the commercial production of HPM. Yeast invertase, a mannoprotein with haze protective activity, was used as a model substrate to investigate the mechanism of haze protection. Invertase was found to reduce visible turbidity but not prevent protein precipitation. Invertase itself did not precipitate but remained soluble in the wine. On the basis of these observations, we propose that the mechanism of haze protection may be one of competition between HPM and wine proteins for unknown wine component(s), the latter being required for the formation of large insoluble aggregates of denatured protein. As the available concentration of these components decreases, due to the presence of HPM, the particle size of the haze decreases and thus visible turbidity declines. 相似文献
17.
中国传统农耕文化与精耕细作的农业精神是中国古代农业长期居于世界领先地位的关键因素。目前传播方式的限制阻碍了农耕文化与精神的传播和发展,鉴于此,提出一种结合虚拟现实技术开发虚拟农耕场景智能展示平台的方法。该研究提出的模型交互控制观察算法,精确地实现了模型的旋转与缩放查看;针对目前虚拟场景路径漫游中漫游物体角度不能变化的问题,提出一种物体朝向变化的虚拟场景漫游算法,使得路径虚拟漫游更贴合人的浏览角度。该研究基于Unity3D平台,采用3d Max建模工具,以C#为脚本语言设计并开发虚拟农耕场景智能展示平台。试验结果表明:虚拟农耕场景融合了交互与漫游技术,可还原古代农耕场景,宣传介绍典型生产技艺,为文化的展示提供参考。 相似文献
18.
Bouras N Mathieu F Coppel Y Strelkov SE Lebrihi A 《Journal of agricultural and food chemistry》2007,55(22):8920-8927
A survey on the occurrence on grape of fungi species in 2001 and their capability to produce ochratoxin A (OTA) and naphtho-gamma-pyrones (NGPs) was conducted in different vineyards from several French viticulture regions. The total numbers of fungal isolates, from setting to harvest, were 732. The Aspergillus genus was essentially represented by section Nigri (98.53%) and it was predominant (74.72%) when compared to Penicillium (25.27%). Approximately one third (30.46%) of the fungal isolates were OTA producers, and 94.17% belong to black aspergilli; Aspergillus carbonarius was the main OTA producer. Moreover, 8.33% of isolates (belong to A. carbonarius and A. niger) were NGP producers. However, none of the Penicillium spp. or other Aspergillus spp. isolates can produces NGP derivatives under the conditions used. No other study on NGPs production by fungi isolated from grapes has been reported. In the second part, a novel NGP, named aurasperone G (1), was isolated from the fermentation broth of the culture extracts of Aspergillus niger C-433, strain producer of OTA, along with the known compound aurasperone F (2). The chemical structure of the new polyketide was proposed based on complete (1)H and partial (13)C, COSY, HMQC, 1D NOE NMR spectra as well as UV and MS spectra. This new NGP was not reported before in nature or prepared synthetically. 相似文献
19.
Biochar has potentials for soil fertility improvement, climate change mitigation and environmental reclamation, and charred biomass can be deliberately incorporated into soil for long-term carbon stabilization and soil amendment. Many different methods have been used for biochar production ranging from laboratory to industrial scales. However, in countryside of developing countries,biomass is generally used for cooking but not charred. Biochar production techniques at farmer scale have remained poorly developed.We developed and tested biochar production kilns for farmers with a dimension of 50.8 cm × 38.1 cm(height × diameter), using three different setups for optimizing oxygen(O2) limitation and syngas circulation: airtight with no syngas circulation(Model I),semi-airtight with external syngas circulation(Model II) and semi-airtight with internal syngas circulation(Model III). A comparative assessment of these biochar production kiln models was made considering biochar pyrolysis time, fuel to biomass ratio, biochar to feedstock ratio and thermogravimetric index(TGI). Among the models, the best quality biochar(TGI = 0.15) was obtained from Model I kiln taking the longest time for pyrolysis(12.5 h) and the highest amount of fuel wood(1.22 kg kg-1biomass). Model III kiln produced comparatively good quality biochar(TGI = 0.11), but with less fuel wood requirement(0.33 kg kg-1biomass) and shorter pyrolysis time(8.5 h). We also tested Model III kiln in a three times larger size under two situations(steel kiln and pit kiln). The biochar to feedstock ratio(0.38) and quality(TGI = 0.14) increased slightly for the larger kilns. Quality of biochar was found to be mainly related to pyrolysis time. The costs for the biochar stove and pit kiln were US$ 65–77, while it was US$ 154 for the large size steel kiln. Model III kiln can potentially be used for both cooking and biochar production at farmer scale. 相似文献
20.
为了真实准确地模拟植物叶片表观颜色,提出一种基于多图像的叶片表观模拟方法。首先搭建基于线性光源的表观图像采集系统,用以获得400张视线角度固定、光源方向变化的叶片图像集合;采用拟合方法自动地从400张图像中获得整个叶片表面的表观特征参数,包括漫反射强度、高光反射强度和粗糙度;利用该拟合方法对线性光源移动条件下理想物体的各种反射特征的变化情况进行仿真计算,然后针对叶片图像中的每个像素寻找与仿真计算结果最接近的表观模型参数作为拟合结果。通过该拟合方法,可将叶片表面上各个位置的表观参数合成3张表观参数图像,采用基于点光源的实时光照方法测试最终的可视化模拟效果。从模拟结果中可以看出利用该文方法得到的结果能够真实地表现叶片自身的表观质感特性,相对于传统方法更加真实准确。 相似文献